ASTM D8370-22
(Test Method)Standard Test Method for Field Measurement of Electrochemical Impedance on Coatings and Linings
Standard Test Method for Field Measurement of Electrochemical Impedance on Coatings and Linings
SIGNIFICANCE AND USE
4.1 This test method is suitable for in-service condition assessment and quality control (QC) testing.
4.2 This technique is used to investigate a polymer barrier coating over a conductive substrate and is limited to exposed and accessible coating surfaces.
4.3 This test method is applicable to polymer barrier coatings of all thicknesses provided the impedance is within equipment capabilities. Special considerations are required for evaluation of coatings exceeding 2 mm thickness or containing conductive media, such as metal pigments and conducting polymers.
4.4 This test method provides the experimental method needed to ensure proper application of field EIS testing and reporting of its results. This test method uses two test cells per measurement with no electrical connection to the substrate (1-4) (a deviation from the traditional three-electrode measurement) to prevent the need for electrical connection to the underlying structure.
Note 1: The two-test-cell method measures the impedances beneath the two cells plus the impedance of the path between them. This arrangement has additional risks of false negatives/positives that are not encountered using the traditional three-electrode measurement in which an electrical connection to the substrate is made. For this test method, a false positive is defined as a higher impedance value than is typical for the coating, and a false negative is defined as a lower impedance value than is typical for the coating. A traditional three-electrode measurement in the field is possible, but a reliable electrical connection to the substrate can be challenging and may require damage to an otherwise good coating.
4.5 This test method may be used at any time during the life of a coating system. If used for QC, allow for any manufacturer’s recommended cure or drying time unless otherwise agreed upon between the participating parties.
Note 2: The results obtained by using this test method could be used for informed coatin...
SCOPE
1.1 This test method covers the procedure for field measurement of electrochemical impedance spectroscopy (EIS) for polymeric coatings over conductive substrates.
1.2 This test method covers the parameters for determining an adequate sample size.
1.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D8370 − 22
Standard Test Method for
Field Measurement of Electrochemical Impedance on
1
Coatings and Linings
This standard is issued under the fixed designation D8370; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope G3 Practice for Conventions Applicable to Electrochemical
Measurements in Corrosion Testing
1.1 Thistestmethodcoverstheprocedureforfieldmeasure-
G106 Practice for Verification of Algorithm and Equipment
ment of electrochemical impedance spectroscopy (EIS) for
for Electrochemical Impedance Measurements
polymeric coatings over conductive substrates.
G193 Terminology and Acronyms Relating to Corrosion
1.2 This test method covers the parameters for determining
G215 Guide for Electrode Potential Measurement
an adequate sample size.
3
2.2 ISO Standards:
1.3 Units—The values stated in SI units are to be regarded
ISO 16773-1 Electrochemical impedance spectroscopy
as standard. No other units of measurement are included in this
(EIS) on coated and uncoated metallic specimens—Part 1:
standard.
Terms and definitions
ISO 16773-2 Electrochemical impedance spectroscopy
1.4 This standard does not purport to address all of the
(EIS) on coated and uncoated metallic specimens—Part 2:
safety concerns, if any, associated with its use. It is the
Collection of data
responsibility of the user of this standard to establish appro-
ISO 16773-3 Electrochemical impedance spectroscopy
priate safety, health, and environmental practices and deter-
(EIS) on coated and uncoated metallic specimens—Part 3:
mine the applicability of regulatory limitations prior to use.
Processing and analysis of data from dummy cells
1.5 This international standard was developed in accor-
ISO 16773-4 Electrochemical impedance spectroscopy
dance with internationally recognized principles on standard-
(EIS) on coated and uncoated metallic specimens—Part 4:
ization established in the Decision on Principles for the
Examples of spectra of polymer-coated and uncoated
Development of International Standards, Guides and Recom-
specimens
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
3. Terminology
2. Referenced Documents
3.1 Definitions—For definitions of terms used in this test
2
2.1 ASTM Standards: method, refer to Terminologies G193 and D16.
D16 TerminologyforPaint,RelatedCoatings,Materials,and
3.2 Definitions of Terms Specific to This Standard:
Applications
3.2.1 test area, n—total area of the coating surface within a
D610 Practice for Evaluating Degree of Rusting on Painted
pair of test cells.
Steel Surfaces
3.2.2 test location, n—discrete physical location(s) selected
D660 Test Method for Evaluating Degree of Checking of
on each structure for performing the electrochemical imped-
Exterior Paints
ance spectroscopy (EIS) measurements.
D661 Test Method for Evaluating Degree of Cracking of
Exterior Paints
4. Significance and Use
D714 Test Method for Evaluating Degree of Blistering of
4.1 This test method is suitable for in-service condition
Paints
assessment and quality control (QC) testing.
1
4.2 This technique is used to investigate a polymer barrier
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of
coating over a conductive substrate and is limited to exposed
Subcommittee D01.48 on Durability of Pipeline Coating and Linings.
and accessible coating surfaces.
Current edition approved March 1, 2022. Published March 2022. DOI: 10.1520/
D8370-22.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
3
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Available from International Organization for Standardization (ISO), ISO
Standards volume information, refer to the standard’s Document Summary page on Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
the ASTM website. Switzerland, https://www.iso.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
D8370 − 22
approaching the limit of the instrument’s input impedance, larger surface
4.3 This test method is applicable to polymer barrier coat-
areas may be needed. Typical test cell materials include a 100 mL plastic
ings of all thicknesses provided the impedance is within
beaker with the
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.